Which reaction occurs at the cathode of a galvanic cell that has an aluminum electron in an electrolyte with aluminum ions in copper electrode in electrolyte with copper ions? The reduction potential for the reduction of Cu^2+ =0.34 V. The reduction potential for the reduction of Al^3+ = -1.68. A. Cu^2+(aq) + 2e- -> Cu(s)
B. Cu(s) -> Cu^2+(aq) + 2e-
C. Al^3+(aq) + 3e- -> Al(s)
D. Al(s) -> Al^3+(aq) + 3e-

Radon-222 or rn-222 has a half-life of 3.82 days. to determine the fraction of an original sample of rn-222 that remains unchanged after 7.646 days, we calculate the amount of rn-222 remaining after 7.646 days and divide it with the original amount. using 1 gram as a basis and using half-life calculation methods, we can determine that  0.249 or 0.25  grams of rn-222 will remain, and thus the fraction remaining is 0.25 or 1/4.

They both go downwards and the can break apart rocks 

Ibelieve it’s 1.95m

Mv^2 is a conserved quantity so v goes as sqrt(1/m) heavier is slower 64/4 = 16 sqrt(16) = 4